An upper bound computational model for investigation of fusion effects on adjacent segment biomechanics of the lumbar spine

Abstract

Prediction of the biomechanical effects of fusion surgery on adjacent segments is a challenge in computational biomechanics of the spine. In this study, a two-segment L3-L4-L5 computational model was developed to simulate the effects of spinal fusion on adjacent segment biomechanical responses under a follower load condition. The interaction between the degenerative segment (L4-5) and the adjacent segment (L3-4) was simulated using an equivalent follower spring. The spring stiffness was calibrated using a rigid fusion of a completely degenerated disc model at the L4-5 level, resulting in an upper bound response at the adjacent (L3-4) segment. The obtained upper bound equivalent follower spring was used to simulate the upper bound biomechanical responses of fusion of the disc with different degeneration grades. It was predicted that as the disc degeneration grade at the degenerative segment decreased, the effect on the adjacent segment responses decreased accordingly after fusion. The data indicated that the upper bound computational model can be a useful computational tool for evaluation of the interaction between segments and for investigation of the biomechanical mechanisms of adjacent segment degeneration after fusion.     

腰椎间盘突出症康复治疗中腰部核心肌力训练的临床评估

为了系统评估腰椎间盘突出症患者康复治疗中腰部核心肌力训练治疗的临床疗效,本研究选取2012年1月至2014年1月研究者所在医院就诊的150例腰椎间盘突出症腰肌锻炼康复治疗患者,随机分成A、B两组。A组患者进行腰部核心肌力训练治疗,即核心肌力组;B组患者给予传统腰肌功能锻炼治疗,即传统腰肌锻炼组;康复治疗均在医生指导下进行,所有患者每天早晚各锻炼1次,每次持续15 min,共训练治疗12周。所有患者均定期随访,治疗后6周和12周分别通过VAS疼痛评分、JOA腰椎功能评分和ODI腰椎功能评分变化进行效果评价。治疗后6周,核心训练组VAS评分平均(5.0±1.5)分,JOA评分平均(21.4±2.6)分,ODI评分平均(29.5±8.0)分;但与传统腰肌训练组比较无明显差别(p>0.05);治疗后12周核心肌力锻炼组疼痛症状缓解明显,VAS平均(2.9±1.2)分;腰椎功能改善明显JOA评分平均(25.2±3.2)分,ODI评分平均(38.8±9.4)分;与传统腰肌训练组比较差异具有统计意义(p<0.05)。本研究说明腰肌核心肌力训练长期锻炼效果好于传统腰肌训练。     

普拉提运动对慢性下腰痛患者的疼痛和腰椎功能的影响

为了揭示普拉提运动对慢性下腰痛患者的疼痛和腰椎功能的影响,本研究选择2017年1月至2018年6月在医院确诊并接受治疗的64例慢性下腰痛患者作为研究对象,根据运动疗法分为对照组(悬吊训练法)和观察组(悬吊训练法结合普拉提运动),采用视觉模拟评分(VAS)评价患者的疼痛程度,采用Oswestry功能障碍指数(ODI)评价患者的腰椎功能障碍情况,采用运动情境动机量表(SSIMS)评价患者的运动参与动机。研究显示,治疗后观察组的VAS评分显著低于对照组(p=0.043)。观察组治疗后的ODI总评分显著低于对照组(p=0.026),观察组患者治疗后的疼痛、生活自理、提物、行走和站立5个维度评分显著低于对照组(p<0.05)。SSIMS量表的4个维度中,鉴别原则得分最高,其次为内部动机,然后是外部调节,最后为缺乏动机。本研究结果提示,普拉提运动可显著降低下腰痛患者的疼痛程度,并改善腰椎功能。此外,普拉提运动具有较好的患者认可度和喜爱度,值得在临床和运动康复训练中应用。     

腰大池持续引流术对老年重型颅脑损伤患者颅内压和并发症及预后的影响

目的:探讨腰大池持续引流术对老年重型颅脑损伤患者颅内压、并发症和预后的影响。方法:选取2014年8月～2018年8月期间成都医学院第一附属医院收治的老年重型颅脑损伤患者60例为研究对象。根据随机数字表法将患者分为对照组(n=30)与研究组(n=30),其中对照组术后给予常规的脱水对症治疗,研究组则在此基础上给予腰大池持续引流术。比较两组术后临床疗效以及并发症,术后3d、5d、7d颅内压,随访半年,观察两组患者预后。结果:研究组治疗后总有效率为90.00%,显著高于对照组患者的66.67%(P0.05)。两组患者术后3d、5d、7d颅内压均较术前降低,且研究组低于对照组(P0.05)。研究组脑梗死、脑水肿、硬膜下积液、癫痫、纵裂积液等并发症发生率均低于对照组(P0.05),而颅内感染比较差异无统计学意义(P0.05)。研究组良好例数高于对照组,而重残以及死亡例数均低于对照组,差异有统计学意义(P0.05);而两组轻残、植物生存例数比较差异无统计学意义(P0.05)。结论:腰大池持续引流术治疗老年重型颅脑损伤患者,疗效满意,可显著改善患者颅内压,减少并发症发生率,改善患者预后,适于临床推广。     

Reevaluation of the lumbosacral region of Oreopithecus bambolii

Functional interpretations of the postcranium of the late Miocene ape Oreopithecus bambolii are controversial. The claim that Oreopithecus practiced habitual terrestrial bipedalism is partly based on restored postcranial remains originally recovered from Baccinello, Tuscany ( Köhler and Moyà-Solà, 1997). The lower lumbar vertebrae of BA#72 were cited as evidence that Oreopithecus exhibits features indicative of a lordotic lumbar spine, including dorsal wedging of the vertebral bodies and a caudally progressive increase in postzygapophyseal interfacet distance. Here, we demonstrate why the dorsal wedging index value obtained by Köhler and Moyà-Solà (1997) for the BA#72 last lumbar vertebra is questionable due to distortion in that region, present a more reliable way to measure postzygapophyseal interfacet distance, and include an additional metric (laminar width) with which to examine changes in the transverse dimensions of the neural arches. We also quantify the external morphology of the BA#72 proximal sacrum, which, despite well-documented links between sacral morphology and bipedal locomotion, and excellent preservation of the sacral prezygapophyses, first sacral vertebral body, and right ala, was not evaluated by Köhler and Moyà-Solà (1997). Measures of postzygapophyseal interfacet distance and laminar width on the penultimate and last lumbar vertebrae of BA#72 reveal a pattern encompassed within the range of living nonhuman hominoids and unlike that of modern humans, suggesting that Oreopithecus did not possess a lordotic lumbar spine. Results further show that the BA#72 sacrum exhibits relatively small prezygapophyseal articular facet surface areas and mediolaterally narrow alae compared with modern humans, indicating that the morphology of the Oreopithecus sacrum is incompatible with the functional demands of habitual bipedal stance and locomotion. The Oreopithecus lumbosacral region does not exhibit adaptations for habitual bipedal locomotion.     

Sarcomere length organization as a design for cooperative function amongst all lumbar spine muscles

The functional design of spine muscles in part dictates their role in moving, loading, and stabilizing the lumbar spine. There have been numerous studies that have examined the isolated properties of these individual muscles. Understanding how these muscles interact and work together, necessary for the prediction of muscle function, spine loading, and stability, is lacking. The objective of this study was to measure sarcomere lengths of lumbar muscles in a neutral cadaveric position and predict the sarcomere operating ranges of these muscles throughout full ranges of spine movements. Sarcomere lengths of seven lumbar muscles in each of seven cadaveric donors were measured using laser diffraction. Using published anatomical coordinate data, superior muscle attachment sites were rotated about each intervertebral joint and the total change in muscle length was used to predict sarcomere length operating ranges. The extensor muscles had short sarcomere lengths in a neutral spine posture and there were no statistically significant differences between extensor muscles. The quadratus lumborum was the only muscle with sarcomere lengths that were optimal for force production in a neutral spine position, and the psoas muscles had the longest lengths in this position. During modeled flexion the extensor, quadratus lumborum, and intertransversarii muscles lengthened so that all muscles operated in the approximate same location on the descending limb of the force-length relationship. The intrinsic properties of lumbar muscles are designed to complement each other. The extensor muscles are all designed to produce maximum force in a mid-flexed posture, and all muscles are designed to operate at similar locations of the force-length relationship at full spine flexion.     

罗哌卡因腰麻联合硬膜外麻醉在剖宫产手术中的应用效果

目的:探讨罗哌卡因腰麻联合硬膜外麻醉在剖宫产手术中的应用效果及安全性,为妇科手术麻醉提供可借鉴的方法。方法:对我院于2012年2月至2013年2月期间收治的100例行剖宫产术患者,均于腰硬联合麻醉方式下进行手术,按照随机数字表法,分为观察组50例与对照组50例,分别使用甲磺酸罗哌卡因与盐酸布比卡因进行麻醉,观察与对比两组患者的麻醉效果与不良反应。结果:观察组患者的运动阻滞起效时间、运动阻滞维持时间均显著低于对照组患者,差异存在统计学意义(P0.05);观察组患者与对照组患者在不良反应方面比较,差异不存在统计学意义(P0.05)。结论:罗哌卡因腰麻联合硬膜外麻醉在剖宫产手术中,产生的麻醉效果快速,且安全可靠性有保障,具备临床推广应用的价值。     

腰椎间盘突出合并脊柱滑脱患者的手术治疗观察

目的:研究手术治疗腰椎间盘突出合并脊柱滑脱的临床疗效。方法:将腰椎间盘突出合并脊柱滑脱的120例患者随机分为两组,其中对照组54例采取保守(非手术)治疗;观察组66例采取手术治疗,对所有接受治疗的患者进行6至9个月不等(平均8个月)的随访,采用视觉模拟评分(VAS)以及腰椎功能障碍指数评分(ODI)两组结果,比较保守和手术治疗的效果。结果:根据VAS和ODI评价结果,手术治疗组疗效明显优于保守治疗组,两治疗组的比较差异具有统计学意义(P0.05)。结论:手术治疗腰椎间盘突出合并脊柱滑脱效果优于保守治疗,是一种安全、有效的方法,能显著改善临床症状,疗效显著。